There are many situations in which airtight doors are necessary to separate two environments. These range from domestic applications such as in refrigerator doors through various commercial and institutional applications. In the last category various types of isolation units such as those in hospitals and research establishments may have particularly strict requirements. One such example of a use in research occurs in virus studies where particular environments exposed to viruses under study must be isolated.
Many solutions have been proposed which are aimed at ensuring the integrity of airtight door seals. In this regard attention has been paid to the seals per se and to some degree to control systems and devices to improve reliability and safety.
To date no airtight door is available which adequately meets the reliability and safety requirements which have become more stringent over the years.
It is against this background that the present invention arises. An airtight door assembly has been devised which is relatively simple in concept but achieves a very high standard of reliability and safety.